<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <script src="./demo12.js"></script>
</head>
<body>
    <form id="loginForm" action="" method="post">
        <input type="text" name="username" id="username" placeholder="请输入用户名"required><br>
        <input type="password" name="password" id="password" placeholder="请输入密码"required><br>
        <input type="checkbox" name="" id="male">男
        <input type="checkbox" name="" id="female">女
        <select name="" id="city">
            <option value="001">乌鲁木齐</option>
            <option value="002">呼和浩特</option>
            <option value="003">南宁</option>
        </select><br>
        <input type="submit" value="登录" onclick="login()">
    </form>
</body>
</html>